The present application is related to closures for beverage containers; and more specifically, to a closure having an open/close type spout and plug, where the sealing surfaces within the closure are reduced and/or are protected from damage, thereby improving the performance and consistency of the closure product. This application is relevant to both push/pull type spouts and to twist open/close spouts.
Prior art closures having an open/close type spout and plug typically include at least two components: a base component that attaches to the throat of a beverage container, and a spout component that is carried on the base component and is adapted to be reciprocated between and open and close position with respect to the base component by a consumer. Typically, the base component includes an opening coaxial with the throat of the beverage container and a coaxial plug extending from the opening, and the spout component includes a coaxial orifice that is in fluid communication with the opening of the base component when the spout is in its open position and that is plugged by the plug of the base component when the spout component is in its closed position. It also known to provide the plugs on the spout component rather than the base component, which cooperate with an orifice on the base component.
With such closures, the base and spout components are typically molded separately from thermoplastic materials and later assembled together in an assembly operation. Furthermore, with such prior art closures, the plugs of the base or spout components extend outwardly from the component. Thus, during the molding process, the plug's sealing surface (which will seal against the corresponding sealing surface of the orifice) can be scratched or damaged due to impacting the mold components while being stripped off or ejected from the cores of the mold. The sealing surface is also subject to slight damage during the sorting and handling that occurs during the automatic assembly process of the closure, as well as the manipulation that occurs during filling and final assembly of the closure to the container. The scratching and damage that occurs can create a seal failure which is more severe when trying to hold a positive or negative pressure in the container.
A third component often included with such closures is a removable overcap component, which is attached over the spout component to the base component to protect the spout component from contamination during shipping and handling. Some prior art overcaps are also capable of being reattached by the consumer after initial removal. There are two common ways to make a prior art overcap tamper-evident (i.e., notify the consumer that the overcap had been previously removed after the initial bottling operation). One way is to design the overcap with a straight wall which locks onto or into the base when applied. The wall is molded with perforations or is cut with perforated blade in a post molding operation. The perforations break; leaving a portion of the wall attached to the base cap when the consumer opens the closure for the first time.
The second common prior art design for a tamper evident overcap has an outer ring that locks into or onto the base cap. The ring is attached to the overcap via bridges. The bridges break the first time the overcap is opened, leaving the ring attached to the base.
Both designs have had limited tamper evident success because the only way the consumer can determine whether the closure has been previously opened is by the feel of the bridges breaking or the sound of the bridges breaking. When the overcap is re-applied after the initial opening, it is difficult to see if the closure has been opened since the overcap is in the same position in relation to the portion that was broken prior to opening.